Squeaky Aux / serpentine belt caused by belt or pully? Video included.

[mikeote]

Heya,

Thanks for looking at my thread. I just replaced the intercooler on my 2003 Passat TDI and now have a squealing belt when the steering wheel is turned. I don't think the belt is as tight as it should be but not 100%. I don't think it was really any thing I did while changing the intercooler. I put the Passat into service position without removing the radiator hoses or electrical wires.

I do have a separate noise which I think is coming from a bearing on it's way out within the Alternator, so I put a wrench on the tensioner pulley to loosen the belt to check the alternator roller, I may have turned the pulley clockwise initially by accident so possibly stretched the belt? Or loosened the tensioner? The tensioner pulley may be vibrating more than it did, I can't remember how much it vibrated before.

Can you guys check out the video and let me know what you think? The steering wheel is being turned while the video is being taken, without it being turned there squeeling is not there.

https://youtu.be/LvloDPFMzow

Cheers!
Mike

[zollaf]

check your alternator freewheel pulley for correct operation and if it is seized, fit a new one.

[Col]

It could be anything that is driven by the aux belt;

Weak tennsioner
Alternator pulley
Viscose fan bearing
Power steering pump

The usual suspencts are the alternator pulley and the tensioner. It would be worth changing them along with a new belt in the first instance.

I did a recent camblet change on my 2004 B5.5 and changed the alt pulley and fan bearing as a precaution along with a new aux belt. I was getting a bit of a chirp when the engine was cold so whilst it was off, did the lot.

[mikeote]

Thanks for the replies guys, I'll go through the car history to see when the belt / pulley were last replaced. Is it possible to check the alternator roller without putting the car into service position? I tried last time but didn't want to risk the belt falling off one of the accessories. I loosened the tensioner as much as I could and the belt was difficult take off the alternator.

Is it possible that I loosened the bolts holding the tensioner on accidentally when I was messing with it? If so perhaps the problem can just be fixed by tightening up those bolts?

Cheers
Mike

[zollaf]

who knows what bolts you may have loosened lol ?
to test the pulley, use a small screwdriver and try to turn the fan of the alternator. it should turn in one direction and not the other. this is with the engine off and nothing else removed.

[mikeote]

Great tip thanks! I tried moving the fan on the alternator with a screw driver, I didn't seem to want to slip either way though I'm not sure how much pressure you're supposed to use. I put enough pressure that there was some deflection of the fan blade. So perhaps that roller is seized... Can you recommend good brands for rollers / belts?

I should have been more clear, I definitely didn't intentionally undo the bolts holding the tensioner pulley on. I was just wandering if I could have made it loose by trying to turn the bolt like extrusion the wrong way using a wrench. Nevermind that question though.

Cheers!

[zollaf]

so it needs a new pulley as i suspected. get one made by gates or ina. gates will be an ina in a gates box. but you need the tool to change it, and a windy gun, but it can be done without moving the front into service, just pull the alternator off and change it on the bench.

[mikeote]

That's great thanks again! I just went over all of the history for my Passat (only had it two months), the cambelt & V belt are now due to be changed so I'll do the alternator pulley at the same time. I'll order an INA cambelt kit (inc water pump / tensioner / idler), as well as INA automatic tensioner / viscous fan bearing (as Col suggested) and V belt if INA make all of these?

Would you guys recommend I change any other pulleys while I'm at it? Power steering etc.

Do I really need an air impact with the spline tool for the alt pulley? Can't I just use a large torque wrench with the spline tool to remove and install the pulleys?

Cheers!

[zollaf]

you can use a large bar to remove the pulley, the kit comes with the torx bit to hold the alternator. but thats the point, you need to stop the alternator turning , which is hard. this is why i recommend using a windy gun. even if you take the alternator to a garage and get them to swop the pulley over for you. with the tool and a windy gun its like a 3 minute job, 1 minute even..

[mikeote]

I'm not sure I follow, the tool you need to do it stops the alternator turning?

Edit: I found the tool I think you may mean:

https://www.amazon.co.uk/Pulley-Cent.../dp/B00HRLJGVE

This can't or would be very awkward to use with a torque wrench so I'm better off going to a garage and asking them to do it, got it .

Would you guys recommend I change any thing else I didn't mention while I'm at it? Power steering pump etc.